Relative Humidity Dependence of Soot Aggregate Restructuring Induced by Secondary Organic Aerosol: Effects of Water on Coating Viscosity and Surface Tension
Relative Humidity Dependence of Soot Aggregate Restructuring Induced by Secondary Organic Aerosol: Effects of Water on Coating Viscosity and Surface Tension
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DOI：
10.1021/acs.estlett.7b00298
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发表时间：
2017-08
影响因子：
10.9
通讯作者：
K. K. Leung-K.;Elijah G. Schnitzler;W. Jäger;J. Olfert
中科院分区：
文献类型：
--
作者：
K. K. Leung-K.;Elijah G. Schnitzler;W. Jäger;J. Olfert
烟尘聚集体对气候具有显著的增温效应，其结构和光学性质可能在涂层的存在下发生变化。本文通过一系列的光氧化实验，研究了二次有机气溶胶（SOA）涂层诱导烟尘聚集体重组的相对湿度（RH）依赖性。燃烧器产生的烟尘聚集体按迁移直径分类，并注入烟雾室，暴露于对二甲苯的氧化产物中；包覆的骨料随后被调理为以下RHs之一：<12%,20%,40%，60%或85%。分别使用微分迁移率和离心式颗粒质量分析仪监测直径和质量的变化。当相对湿度< 12%时，由于SOA涂层黏性太大，无法引起结构重构，因此颗粒直径随涂层质量的增加而均匀增加。当相对湿度≥20%时，SOA涂层引起结构重构，且结构重构程度随相对湿度的增加而增加。
Soot aggregates have a significant warming effect on climate, and their structural and optical properties may evolve in the presence of coatings. Here, the relative humidity (RH) dependence of soot aggregate restructuring induced by secondary organic aerosol (SOA) coatings was investigated in a series of photo-oxidation experiments. Burner-generated soot aggregates were classified by mobility diameter and injected into a smog chamber, where they were exposed to oxidation products of p-xylene; coated aggregates were subsequently conditioned at one of the following RHs: <12%, 20%, 40%, 60%, or 85%. Changes in diameter and mass were monitored using differential mobility and centrifugal particle mass analyzers, respectively. At RH < 12%, the SOA coating was too viscous to induce restructuring, so the particle diameter increased uniformly with coating mass. At RH ≥ 20%, the SOA coating induced restructuring, and the degree of restructuring increased with RH, indicating that the decreased viscosity and increase...